In a semiconductor device, part of the current flowing in the device section may leak to the outside of the device section. The current like this is referred to as e.g. leakage current. The leakage current causes increased power consumption of the semiconductor device. Furthermore, in the case where a plurality of device sections are provided on a semiconductor substrate, the leakage current may flow into another adjacent device section. This causes malfunctions of the other device section or noise in the signal flowing in the other device section. Thus, suppression of leakage current is desired in the semiconductor device.